What is Construct validity?
Construct validity is the degree to which a test or measure actually captures the theoretical construct it claims to measure. A measure has high construct validity when it behaves as theory predicts the construct should behave.
How it works
Assessing construct validity involves testing whether the measure correlates with measures of related constructs (convergent validity), does not correlate with measures of unrelated constructs (discriminant validity), and produces results consistent with theoretical predictions (nomological validity). A depression scale with high construct validity should correlate with clinical diagnoses, predict functional impairment, and decrease when effective treatment is administered.
Applied example
An intelligence test that strongly predicts academic performance (as IQ theory predicts) but also correlates equally with socioeconomic status and test-taking familiarity may be measuring a confound of intelligence and privilege rather than intelligence alone, indicating questionable construct validity.
Why it matters
Construct validity determines whether research findings are about what they claim to be about, making it the foundation of meaningful scientific measurement.
